Cascade reactions

级联反应
  • 文章类型: Journal Article
    具有器官样三维结构的多糖基水凝胶的合理设计为解决同种异体移植组织和器官的短缺提供了很大的可能性。然而,在整体水凝胶中对结构的时空控制和获得满意的机械性能仍然是实现的内在挑战。这里,我们展示了电场辅助分子自组装如何耦合到定向反应-扩散(RD)过程,以可控的方式产生宏观水凝胶。电能输入不仅能产生复杂的分子梯度,还能引发分子自组装,而且还通过级联构建相互作用来指导/促进凝胶快速生长的RD过程。可以通过使用互穿生物聚合物网络和多种离子交联剂来调节和增强水凝胶的机械性能,导致广泛的机械模量与生物器官或组织相匹配。我们证明了可以通过场辅助的定向反应扩散和特定的联合相互作用轻松制备各种3D宏观水凝胶。功能梯度的谦卑触发的消散和抗菌性能证实了水凝胶可以用作用于伤口管理的光学可变软装置。因此,这项工作为合理制造具有受控结构和功能的软水凝胶提供了一种通用方法,用于先进的生物医学系统。
    Rational designs of polysaccharide-based hydrogels with organ-like three-dimensional architecture provide a great possibility for addressing the shortages of allograft tissues and organs. However, spatial-temporal control over structure in bulk hydrogel and acquire satisfied mechanical properties remain an intrinsic challenge to achieve. Here, we show how electric-field assisted molecular self-assembly can be coupled to a directional reaction-diffusion (RD) process to produce macroscopic hydrogel in a controllable manner. The electrical energy input was not only to generate complex molecule gradients and initiate the molecular self-assembly, but also to guide/facilitate the RD processes for the gel rapid growth via a cascade construction interaction. The hydrogel mechanical properties can be tuned and enhanced by using an interpenetrating biopolymer network and multiple ionic crosslinkers, leading to a wide-range of mechanical modulus to match with biological organs or tissues. We demonstrate diverse 3D macroscopic hydrogels can be easily prepared via field-assisted directional reaction-diffusion and specific joint interactions. The humility-triggered dissipation of functional gradients and antibacterial performance confirm that the hydrogels can serve as an optically variable soft device for wound management. Therefore, this work provides a general approach toward the rational fabrication of soft hydrogels with controlled architectures and functionality for advanced biomedical systems.
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  • 文章类型: Journal Article
    公开了通过钯驱动的级联反应获得2-烷氧基喹啉衍生物的新合成策略。与基于2-喹诺酮与烷基卤化物烷基化的经典方法不同,本发明的方法受益于从1,3-丁二烯基酰胺开始的喹啉核的从头组装。具有N-(2-碘苯基)-N-甲苯磺酰基-1,3-丁二炔酰胺和伯醇作为外部亲核试剂的钯催化反应级联在温和的反应条件下进行,并在单批转化中选择性地递送多种不同官能化的4-烯基2-烷氧基喹啉。
    A novel synthesis strategy to access 2-alkoxyquinoline derivatives via a palladium-driven cascade reaction is disclosed. Unlike classic methods based on the alkylation of 2-quinolones with alkyl halides, the present method benefits from the de novo assembly of the quinoline core starting from 1,3-butadiynamides. Palladium-catalyzed reaction cascades with N-(2-iodophenyl)-N-tosyl-1,3-butadiynamides and primary alcohols as external nucleophiles proceed under mild reaction conditions and selectively deliver a variety of differently functionalized 4-alkenyl 2-alkoxyquinolines in a single batch transformation.
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  • 文章类型: Journal Article
    在这里,我们报告了两种重排的替利烷二萜的不对称总合成,高光耳曲酸A和pedrolide。进行还原性二羟基化级联反应和Nazarov环化反应,以生成高舒曲酸盐A,经历了Eu促进的二烯基烯醇化的级联,分子内Diels-Alder反应和烯醇-酮互变异构化得到pedrolide,与我们对pedrolide生物发生的建议一致的途径。
    Here we report the asymmetric total syntheses of two rearranged tigliane diterpenoids, euphordraculoate A and pedrolide. A reductive dihydroxylation cascade and Nazarov cyclization were performed to generate euphordraculoate A, which was subjected to a cascade of Eu-promoted dienyl enolization, intramolecular Diels-Alder reaction and enol-ketone tautomerization to afford pedrolide, a pathway consistent with our proposal for the biogenesis of pedrolide.
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  • 文章类型: Journal Article
    背景:通过涉及乙炔二甲酸二甲酯的一锅三组分反应合成了一系列新型2-(异喹啉-1-基)-螺[羟吲哚-3,3'-吡咯啉],3-苯基咪唑并[5,1-a]异喹啉和N-烷基明胶在氯仿中在〜60°C下持续24小时。
    目的:本研究旨在合成新型螺羟吲哚-3,3'-吡咯啉衍生物,并在体外评估其抗炎和自由基清除能力的交叉相关性中的细胞毒性亲和力。
    目的:本研究的目的是使用一罐,三组分反应合成一组新型螺羟吲哚-3,3'-吡咯啉衍生物。
    方法:通过涉及乙炔二羧酸二甲酯的一锅三组分反应合成了一组新型的螺羟吲哚-3,3'-吡咯啉(8a-i),3-苯基咪唑并[5,1-a]异喹啉和N-烷基异喹啉在氯仿中在〜60°C持续24小时。这些新化合物通过1HNMR表征,13C-NMR,和HRMS光谱数据,并筛选其抗肿瘤,抗炎,抗菌,抗真菌药,和抗氧化活性。
    结果:新的合成的螺羟吲哚-3,3'-吡咯啉(8a-i)-测试的化合物显示出显著的抗炎性质并且对PDL成纤维细胞无细胞毒性。然而,它们缺乏抗氧化-DPPH自由基清除能力。值得注意的是,阿霉素和顺铂对各种癌症单层具有抗增殖作用。此外,化合物8b,8d,8f,8h,和8i在结直肠癌和胰腺癌单层中表现出明显的生存力降低特性,以及跨皮肤,肺,前列腺,和宫颈腺癌,在乳腺癌细胞MCF7和T47D中具有较高的细胞毒性。测试的化合物对金黄色葡萄球菌或大肠杆菌都没有显著的抗菌活性。然而,化合物8c,8d,和8f表现出显著的抗真菌特性,表明进一步调查的潜力。
    结论:制备了八种新的合成螺[二氢吲哚-3,3-吡咯],characterized,并评估了它们的抗炎和细胞毒性。这些化合物对各种癌症单层显示出显着的抗炎作用和有希望的细胞毒性,尤其是结直肠癌和胰腺癌。一些化合物还表现出抗真菌性质。然而,它们没有表现出显著的抗菌活性。
    BACKGROUND: A series of novel 2-(isoquinolin-1-yl)-spiro[oxindole-3,3\'-pyrrolines] were synthesized by a one-pot three-component reaction involving dimethyl acetylenedicarboxylate, 3- phenylimidazo[5,1-a]isoquinoline and N-alkylisatins in chloroform at ∼60 °C for 24 h.
    OBJECTIVE: This study aimed at the synthesis of novel spirooxindole-3,3\'-pyrrolines derivatives and in vitro evaluation of cytotoxicity affinities in cross-correlations with their antiinflammation and radical scavenging capacities.
    OBJECTIVE: The objective of this study was to use a one-pot, three-component reaction to synthesize a novel set of spirooxindole-3,3\'-pyrrolines derivatives.
    METHODS: A novel set of spirooxindole-3,3\'-pyrrolines (8a-i) was synthesized by a one-pot threecomponent reaction involving dimethyl acetylenedicarboxylate, 3-phenylimidazo[5,1-a]isoquinoline and N-alkylisatins in chloroform at ∼60 °C for 24 h. These new compounds were characterized by 1HNMR, 13C-NMR, and HRMS spectral data and screened for their antitumor, anti-inflammatory, antibacterial, antifungal, and antioxidant activities.
    RESULTS: The new synthetic spirooxindole-3,3\'-pyrrolines (8a-i)-tested compounds displayed significant anti-inflammatory properties and were noncytotoxic on PDL fibroblasts. However, they lacked antioxidative-DPPH radical scavenging capabilities. Notably, Doxorubicin and cisplatin demonstrated antiproliferative effects on various cancer monolayers. Moreover, compounds 8b, 8d, 8f, 8h, and 8i exhibited pronounced viability reduction properties in colorectal and pancreatic cancer monolayers, as well as across skin, lung, prostate, and cervical adenocarcinomas, with higher cytotoxicity in mammary cancer cells MCF7 and T47D. None of the tested compounds had significant antibacterial activity against S. aureus or E. coli. However, compounds 8c, 8d, and 8f exhibited notable antifungal properties, indicating potential for further investigation.
    CONCLUSIONS: Eight new synthetic spiro[indoline-3,3-pyrroles] were prepared, characterized, and evaluated for their anti-inflammatory and cytotoxic properties. The compounds showed significant anti-inflammatory effects and promising cytotoxicity against various cancer monolayers, especially in colorectal and pancreatic cancers. Some compounds also exhibited antifungal properties. However, they did not exhibit significant antibacterial activity.
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  • 文章类型: Journal Article
    固定化是应用生物催化中促进分离的关键使能技术,recovery,和非均相生物催化剂的再利用。然而,找到形成多酶系统的几种酶的一致固定方案是非常困难的,并且依赖于组合的试错方法。在这里,我们描述了一种方案,其中在96孔微量滴定板中测试了用不同反应基团官能化的17种不同载体,以筛选多达18种酶的多达21种固定化方案。该筛选包括活性和稳定性测定,以选择最佳的固定化化学,以实现最具活性和稳定的非均相生物催化剂。可以使用基于Python的应用程序CapiPy对从筛选中检索到的信息进行合理化。最后,通过对筛查结果进行评分,我们发现共识固定化方案可以组装固定化四酶系统,将乙酸乙烯酯转化为(S)-3-羟基丁酸。该方法为加快用于化学制造的固定化多酶途径的原型化开辟了途径。
    Immobilization is a key enabling technology in applied biocatalysis that facilitates the separation, recovery, and reuse of heterogeneous biocatalysts. However, finding a consensus immobilization protocol for several enzymes forming a multi-enzyme system is extremely difficult and relies on a combinatorial trial-and-error approach. Herein, we describe a protocol in which 17 different carriers functionalized with different reactive groups are tested in a 96-well microtiter plate to screen up to 21 immobilization protocols for up to 18 enzymes. This screening includes an activity and stability assay to select the optimal immobilization chemistry to achieve the most active and stable heterogeneous biocatalysts. The information retrieved from the screening can be rationalized using a Python-based application CapiPy. Finally, through scoring the screening results, we find the consensus immobilization protocol to assemble an immobilized four-enzyme system to transform vinyl acetate into (S)-3-hydroxybutyric acid. This methodology opens a path to speed up the prototyping of immobilized multi-enzyme pathways for chemical manufacturing.
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  • 文章类型: Journal Article
    在本文中,我们报告说,容易获得的4-烯醇酯可被视为有效的二烯醇化物等效物。例如,通过流感诱导的开环步骤,然后通过乙烯基分子内醛醇缩合进行闭环,将衍生自4-烯基氨基香豆素的乳糖甲硅烷基醚选择性地转化为相应的苯并高苯二甲酸酯。同样,4-烯基氨基香豆素的nu-亲清活化直接产生多种多取代的萘和蒽,而不会形成任何区域异构体。对一组由此获得的1,3-二-和1,3,4-三取代蒽的光物理评估揭示了它们在极性溶液中的光吸收过程中的分子内电荷转移(ICT)特性,以及当面对面π堆叠的分子组装时从固态发射的受激准分子存在于晶体堆积中。
    Herein we report that readily available 4-alkenylisocoumarins can be regarded as potent dienolate equivalents. For example, lactol silyl ethers derived from 4-alkenylisocoumarins were selectively converted to the corresponding benzo-homophthalates through a fluoride-induced ring opening step that was followed by a ring closure through a vinylogous intramolecular aldol condensation. Likewise, nucleophilic activation of 4-alkenylisocoumarins directly yields diversely poly-substituted naphthalenes and anthracenes without formation of any regioisomer. Photophysical evaluation of a set of thus obtained 1,3-di- and 1,3,4-trisubstituted anthracenes reveals their distinct intramolecular charge transfer (ICT) character during light absorption in polar solutions and excimer emission from the solid state when a face-to-face π-stacked molecular assembly is present in the crystal packing.
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  • 文章类型: Journal Article
    喹唑啉是一类重要的杂环化合物,已证明其重要性,特别是在有机合成和药物化学领域,因为它们具有广泛的生物学和药理学性质。因此,已经开发了许多合成方法来合成喹唑啉及其衍生物。本文简要概述了采用过渡金属催化反应合成含喹唑啉支架化合物的新方法。
    Quinazolines are an important class of heterocyclic compounds that have proven their significance, especially in the field of organic synthesis and medicinal chemistry because of their wide range of biological and pharmacological properties. Thus, numerous synthetic methods have been developed for the synthesis of quinazolines and their derivatives. This review article briefly outlines the new synthetic methods for compounds containing the quinazoline scaffold employing transition metal-catalyzed reactions.
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  • 文章类型: Journal Article
    纳米酶,作为天然酶的替代品,由于其固有的催化特性,被构造为生物医学应用的级联催化系统,高稳定性,可调谐的物理化学性质,和环境响应性。在这里,据报道,一种多功能纳米酶可在酸性环境中针对耐药幽门螺杆菌(H.幽门螺杆菌)靶向根除。基于钴涂层的普鲁士蓝类似物的FPB-Co-ChNP显示氧化-,超氧化物歧化酶-,过氧化物酶-,和过氧化氢酶-模拟触发•O2-${\\mathrm{O}}_2^-{\\bm{\\}$和H2O2的活动,从而杀死胃中的幽门螺杆菌。为此,通过对壳聚糖进行表面改性,发挥细菌靶向粘附力,提高复合材料的生物相容性。在肠道环境中,级联酶活性被显著抑制,确保治疗的生物安全性。体外,培养幽门螺杆菌的敏感和耐药菌株,并评估其抗菌活性。在体内,小鼠感染模型的发展和其成功是由胃粘膜再培养证实,革兰氏染色,H&E染色,和Giemsa染色。此外,抗菌能力,抗炎,修复效果,并对FPB-Co-ChNPs的生物安全性进行了全面调查。这种策略提供了一种无药物的方法,可以特异性地靶向和杀死幽门螺杆菌,修复受损的胃粘膜,同时缓解炎症。
    Nanozymes, as substitutes for natural enzymes, are constructed as cascade catalysis systems for biomedical applications due to their inherent catalytic properties, high stability, tunable physicochemical properties, and environmental responsiveness. Herein, a multifunctional nanozyme is reported to initiate cascade enzymatic reactions specific in acidic environments for resistant Helicobacter pylori (H. pylori) targeting eradication. The cobalt-coated Prussian blue analog based FPB-Co-Ch NPs displays oxidase-, superoxide dismutase-, peroxidase-, and catalase- mimicking activities that trigger • O 2 - ${\\mathrm{O}}_2^ - {\\bm{\\ }}$ and H2O2 to supply O2, thereby killing H. pylori in the stomach. To this end, chitosan is modified on the surface to exert bacterial targeted adhesion and improve the biocompatibility of the composite. In the intestinal environment, the cascade enzymatic activities are significantly inhibited, ensuring the biosafety of the treatment. In vitro, sensitive and resistant strains of H. pylori are cultured and the antibacterial activity is evaluated. In vivo, murine infection models are developed and its success is confirmed by gastric mucosal reculturing, Gram staining, H&E staining, and Giemsa staining. Additionally, the antibacterial capacity, anti-inflammation, repair effects, and biosafety of FPB-Co-Ch NPs are comprehensively investigated. This strategy renders a drug-free approach that specifically targets and kills H. pylori, restoring the damaged gastric mucosa while relieving inflammation.
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  • 文章类型: Journal Article
    光化学反应的开始通过可持续实践彻底改变了合成化学。这篇综述探讨了利用光诱导过程在没有催化剂的情况下产生级联C-C和C-杂键的前沿发展。重要的是,无催化剂的光诱导方法已经引起了相当大的关注,特别是在创建用于药物设计和天然产物合成的各种杂环框架方面。这篇文章深入研究了潜在的机制,解决限制,并评估各种方法,强调光催化剂和无过渡金属光化学反应的潜力,以增强可持续性。分为两部分,它涵盖了C-C和C-杂原子以及多个C-杂原子键形成反应的最新进展。
    The beginning of photochemical reactions revolutionized synthetic chemistry through sustainable practices. This review explores cutting-edge developments in leveraging light-induced processes for generating cascaded C-C and C-hetero bonds without catalysts. Significantly, catalyst-free photoinduced methodologies have garnered considerable attention, especially in the creation of varied heterocyclic frameworks for drug design and the synthesis of natural products. The article delves into underlying mechanisms, addresses limitations, and evaluates various methodologies, emphasizing the potential of photocatalyst and transition metal-free photochemical reactions to enhance sustainability. Divided into two sections, it covers recent strides in C-C and C-heteroatom and multiple C-heteroatom bond formation reactions.
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  • 文章类型: Journal Article
    植物甾醇(PSs),一类天然存在的生物活性脂质化合物,已经发现具有显著的降胆固醇作用。在发展中国家,油菜籽油的消费是一般人群PS摄入的主要途径。然而,开发低成本,实时,和PSs的高通量筛选技术仍然是一个挑战。这里,通过HKUST-1煅烧的简单方法合成了Cu基纳米复合材料CuOx@C,并通过扫描电子显微镜对其进行了系统表征,透射电子显微镜,X射线衍射,和X射线光电子能谱。CuOx@C表现出优异的过氧化物酶样(POD样)活性,充当过氧化物酶模拟物,以促进3,3'的催化,5,5'-四甲基联苯胺(TMB)为其氧化形式(oxTMB),从而启动可辨别的颜色响应。在这一发现的基础上,通过级联反应成功构建了一种基于CuOx@C的比色法,用于检测油菜籽中的总甾醇。优化条件后,油菜籽中总甾醇的高通量筛选仅需21分钟,这极大地促进了PS的感知。油菜籽样品中总甾醇的检测线性范围为0.6-6mg/g,从而满足检测的要求。此外,由于CuOx@C的高稳定性和胆固醇氧化酶的特异性,所开发的方法对PS具有优异的稳定性和选择性,表明这项工作具有巨大的商业应用前景。这项创新工作克服了仪器方法的局限性,并提供了一种便携式可靠的总甾醇检测工具。它还可以促进具有高PSs含量的油料种子的发育。
    Phytosterols (PSs), a class of naturally occurring bioactive lipid compounds, have been found to possess a significant cholesterol-lowering effect. In developing countries, the consumption of rapeseed oil is the primary pathway of PS intake for the general population. However, developing low-cost, real-time, and high-throughput screening techniques for PSs remains a challenge. Here, a Cu-based nanocomposite CuOx@C was synthesized via a simple method of the calcination of HKUST-1 and systematically characterized by scanning electron microscopy, transmission electron microscopy, X-ray diffraction, and X-ray photoelectron spectroscopy. The CuOx@C demonstrated excellent peroxidase-like (POD-like) activity, functioning as a peroxidase mimic to facilitate the catalysis of 3,3\',5,5\'-tetramethylbenzidine (TMB) into its oxidized form (oxTMB), thereby initiating a discernible color response. On the basis of this discovery, a CuOx@C-based colorimetric method for detecting total sterols in rapeseed was successfully constructed via cascade reactions. After optimizing the conditions, the high-throughput screening of total sterols in rapeseed could be completed in only 21 min, which significantly facilitated the sensing of PSs. A linear range of 0.6-6 mg/g was achieved for the detection of total sterols in rapeseed samples, thereby satisfying the requirements for detection. In addition, due to the high stability of CuOx@C and the specificity of cholesterol oxidase, the developed method had excellent stability and selectivity toward PSs, indicating that this work has huge prospects for commercial application. This innovative work overcomes the limitation of the instrumental method and provides a portable and reliable tool for total sterols detection. It can also facilitate the development of oilseeds with a high content of PSs.
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